1. Field of the Invention
This invention relates to a lightweight steam iron made of plastic material and of the electrolytic version wherein steam is generated by applying current to internal electrodes to provide saturated steam to the ironing surface. A specific arrangement is provided in the structure of the spaced electrodes which, in combination with stop means and plate-area reducing means for each plate, cooperate to prevent mineral build-up and arcing between the plates and stop means.
2. Description of the Prior Art
Irons using plastic for as many parts as possible have come into general use. Typically, such irons may be electrolytic wherein a molded plastic casing contains an internal water tank with spaced electrodes generating steam and a soleplate integral with the water tank is provided as shown in U.S. Pat. Nos. 3,755,649 and 3,969,607. Such irons use plastic soleplates of appropriate material and some can be operable horizontally as an iron, or vertically as a steamer, as shown in U.S. Pat. No. Re 28,418. Such irons or steamers use the plastic soleplate as one side of the tank wall to abut the internal water tank directly against the soleplate whereby its temperature is limited to the temperature of the water. This also permits the use of many different types of plastic soleplates and is generally the type of U.S. Pat. No. Re 28,418. Such arrangements do not permit the use of metallic soleplates because of sealing difficulties even though metallic soleplates may be preferred to permit operation at higher temperatures needed in many ironing operations. A structure permitting this is shown in application Ser. No. 884,765 filed Mar. 9, 1978 of common assignment. Additionally, electrolytic steam generation is common in other than iron applications and usually involves the use of an electrolyte solution with spaced electrodes in one form of another. One of the difficulties has always been the mineral build-up on the plates causing shorting or arcing and this has been reduced in iron applications in some irons by the use of wire electrodes. However, plate electrodes provide much greater steam generating area and are thus desirable as shown in said copending application. There is a need for a special structural arrangement of such electrode plates in an iron combination to provide characteristics necessary for successful operation of an electrolytic iron using plates that can successfully overcome the deficiencies of a build-up of mineral deposits that may later become conductive and result in electrical flash-over that would erode the plates to an unacceptable level. An arrangement is desired where barriers in the form of stops are needed which must, by themselves, not serve as flash-over pathways and such arrangement must provide that every potential source of conduction through the mineral build-ups is neutralized or avoided.